This application claims the priority of German Patent Document 102 19 696.6, filed May 2, 2002, the disclosure of which is expressly incorporated by reference herein.
The invention relates to an air outlet nozzle for a ventilation system, comprising a nozzle housing which has an outlet mouth, a nozzle mouth element and a displacer which is arranged in an airflow in a mouth region and is connected to the nozzle mouth element.
In the case of ventilation devices for vehicles, air outlet nozzles are in practice used with control devices which enable the emerging air jet to be controlled in a specific manner. It is endeavoured here also to control the spreading of the jet in addition to the direction of the air jet. It has been demonstrated that temperature regulation which is more efficient in terms of energy than a focussed air jet can thus be obtained.
Experience has shown that a vehicle occupant diverts a focussed and temperature-regulated air jet away from himself after a certain time, in order to avoid unpleasant drafts. This means that the heating and cooling power has to be increased in order to provide a pleasant temperature for the occupant, since the air jet does not directly heat or cool the occupant, but rather primarily heats or cools other objects in the vehicle. If, in contrast, the occupant has a diffuse air jet aimed directly at him, then draughts are avoided and the heating and cooling power can be reduced.
European Patent Document EP 0 324 770 B1 discloses an air outlet nozzle which has three air-guiding louvres which can be displaced with respect to one another. The air-guiding louvres are arranged in the air exit plane of the air outlet nozzle, one air-guiding louvre being connected fixedly to the nozzle and two of the louvres being displaceable parallel to the fixedly mounted air-guiding louvre. Displacement of the air-guiding louvres causes air-guiding surfaces differing in inclination to be formed, with the result that the exit direction of the air jet can be controlled. It is disadvantageous here that the air-guiding louvres have a high flow resistance and that only the air exit direction, but not the spreading of the air jet, can be controlled.
German Patent Document DE 41 39 099 C2 and corresponding U.S. Pat. No. 5,340,358 discloses an air outlet which has a rotationally symmetrical housing and a rigid baffle plate. The latter is arranged in a fixed position in the outlet cross section of the air outlet. Swirl vanes are arranged in a radially circulating manner in the interior of the housing. Axial displacement of the swirl vanes within the air outlet enables the diffusivity of the emerging air jet to be controlled. The high flow obstruction caused by the swirl vanes, which results in large losses, is disadvantageous here.
German Patent Document DE 196 12 764 C2 shows an air outlet having swirl vanes arranged in a fixed position in the air exit plane. An axially displaceable air-guiding pipe for changing the diffusivity of the emerging airflow is arranged in the interior of the air outlet. High flow losses as a consequence of the large flow obstruction also occur here.
British Patent Document GB 624,932 shows an air outlet nozzle having a fixed baffle plate and a housing having a radial inlet. Air-guiding elements are arranged in an axially adjustable manner in the interior of the housing. Depending on the axial position of the air-guiding elements, the latter, together with the baffle plate, divert the air flowing radially into the nozzle housing by between 180 and 90 degrees, with the result that the air exits in a manner adjusted radially or axially. A disadvantage here is the relatively large structural volume of the air nozzle which is caused by the radial air entrance direction. Also, the flow resistance of this air outlet nozzle is relatively high as a consequence of the air being deflected.
The present invention has an aspect of providing an air outlet nozzle which is of compact design and in which the air jet can be adjusted in diffusivity, and which has a large obtainable spreading of the air jet with low flow losses. The air outlet nozzle is intended preferably to be simple and/or comfortable to operate and is intended not to make much noise.
This aspect may be achieved in that a position of the displacer is suitable in an axial direction relative to the outlet mouth by the displacer being displaceable from a position in the outlet mouth into a position outside the nozzle housing, and wherein the displacer has an adjustable flow obstruction.
A displacer, which can be displaced axially, i.e. can be displaced in the direction of the central longitudinal axis of the air outlet nozzle, is arranged in the mouth region of the air outlet nozzle and has an adjustable flow obstruction. The displacer can be arranged in the mouth region of the air nozzle, in the air outlet plane thereof, or else can be brought outwards out of the mouth region, so that it is arranged outside the nozzle housing. Interaction of the position of the displacer relative to the air exit plane, on the one hand, and of the adjustable flow obstruction of the displacer, on the other hand, enables the flow and pressure ratios in the mouth region of the air outlet nozzle or downstream of the mouth region to be controlled in a specific manner. This results in the airflow emerging from the air outlet nozzle can be controlled in its spreading of the jet and in its diffusity and/or direction. The flow obstruction caused by the displacer and therefore the flow losses which occur are small, since, in the case of a large displacement effect or flow obstruction, the displacer is arranged outside the nozzle housing.
Provision is made, for the flow characteristics of the displacer to be changed by changing its cross section and/or shape. For this purpose, the displacer can have pivotable slats which are preferably arranged in the shape of a V or annularly. Adjustment of the slats causes the shape or the cross section of the displacer to be changed.
In one embodiment of the invention, the displacer may have an elastic membrane which interacts with the slats or with the bars or bar-shaped slats and forms a rounded outer contour of the displacer. In this case, the entire outer contour or individual boundary surfaces of the displacer can be formed by the elastic membrane.
Another embodiment of the invention provides an air-permeable displacer, the air permeability of which can be adjusted. The air permeability can be adjusted in such a manner that the displacer has minimal flow resistance, i.e. maximal air permeability, in the position in which it is not drawn out, i.e. in the region of the mouth plane, and/or maximal flow resistance, i.e. minimal air permeability, in the drawn-out position, i.e. outside the nozzle housing.
The displacer may, in order to make different flow profiles possible, have air permeability which is homogeneous over its cross section or inhomogeneous air permeability.
In order to control the exit direction of the air jet, provision may be made for the displacer to have inhomogeneous air permeability, i.e. differing air permeability in locally delimited areas. The displacer may preferably have a plurality of laminated perforated plates with the pattern of holes differing or louvres with differing pitch, with the result that, depending on the position of the perforated plates or louvres with respect to one another, locally different air permeability can be set. As a result, it is possible to deflect the air jet in a specific direction. Also, by controlling the inhomogeneous air permeability of the displacer, a temporally changeable, preferably periodic control of the exit direction of the air jet is possible. Tilting of the displacer relative to the air exit cross section likewise makes directional setting of the emerging air jet possible.
Yet another embodiment of the invention makes provision for the displacer to be connected to a nozzle mouth element which can be drawn axially out of the nozzle housing. The side walls of the nozzle mouth element have cutouts for the radial exit of air, with the result that only a small flow impediment occurs, if at all. Provision is made for the nozzle mouth element to have basically the same cross section and/or diameter as the nozzle housing, with it being possible for the cross section and/or diameter of the nozzle mouth element to be slightly larger or smaller than that of the nozzle housing, so that the walls of the nozzle mouth element bear inside or outside the nozzle housing in a form-fitting, shapewise or congruent manner on the side walls thereof.
The nozzle mouth element may also be mounted in an axially displaceable manner via guide rails arranged on the side walls of the nozzle housing. Similarly, a central guide rail arranged centrally in the nozzle housing may be provided.
In a structurally simple embodiment, the displacer may be arranged in a fixed position outside the nozzle housing or in the outlet mouth.
One advantageous embodiment makes provision for the nozzle housing to have an adjusting device. The adjusting device may have mechanical and/or electric and/or mechatronic actuators for adjusting the position and/or shape and/or cross section and/or air permeability of the displacer. In particular, the adjusting device can be operated mechanically and/or automatically, preferably can be remote-controlled, so that the outlet direction and/or diffusivity of the air jet can be controlled manually via the adjusting device and/or after a preselectable program sequence or time lapse.
The air exit nozzle is provided, in particular, for use in heating and/or air conditioning and/or ventilation systems for vehicles. Particularly in the case of passenger vehicles, there is the desire to control the air exit of the heating and/or air-conditioning system in such a manner that, in addition to a directed air exit at high speed, a diffuse air exit at low speed can be set, in order, for example, to avoid unpleasant drafts. In this case, the air outlet nozzle must be comfortable, i.e. must make as little noise as possible, and is to take up as little structural space as possible.
Further features and embodiments of the invention emerge from the claims, the figures and the description of the figures. The features and combinations of features mentioned above and presented in the following text can be used not only in the respectively stated combination, but also in other combinations or on their own without departing from the scope of the invention.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.